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authorNicholas Noll <nbnoll@eml.cc>2021-11-11 16:31:58 -0800
committerNicholas Noll <nbnoll@eml.cc>2021-11-11 16:31:58 -0800
commit9695ea005d4af93dcd60f74f10fd3c54499a182f (patch)
tree3e1a9abb9456ba07c0c97cd3d691f6a2df115791 /sys/base/rng/random.c
parentc65794b50b1bc729e7a4e940b76a973afa3030b9 (diff)
chore: split up base library into individual files for smaller binaries
Diffstat (limited to 'sys/base/rng/random.c')
-rw-r--r--sys/base/rng/random.c33
1 files changed, 33 insertions, 0 deletions
diff --git a/sys/base/rng/random.c b/sys/base/rng/random.c
new file mode 100644
index 0000000..bd1bd6b
--- /dev/null
+++ b/sys/base/rng/random.c
@@ -0,0 +1,33 @@
+#include "internal.h"
+
+static uint64
+xoshiro256ss(Rng *state)
+{
+ uint64 *s = state->s;
+ uint64 result = rol64(s[1] * 5, 7) * 9;
+ uint64 t = s[1] << 17;
+
+ s[2] ^= s[0];
+ s[3] ^= s[1];
+ s[1] ^= s[2];
+ s[0] ^= s[3];
+
+ s[2] ^= t;
+ s[3] = rol64(s[3], 45);
+
+ return result;
+}
+
+double
+rng·random(void)
+{
+ uint64 r = xoshiro256ss(&rng·RNG);
+ return (double)r / (double)UINT64_MAX;
+}
+
+uint64
+rng·randi(int max)
+{
+ uint64 r = xoshiro256ss(&rng·RNG);
+ return r % max;
+}